CN1024023C - Process for the preparation of difluorobenzamide - Google Patents

Abstract

The invention provides a process for the preparation of 2,6-difluorobenzamide which comprises subjecting 2,6-difluorobenzonitrile to the action of a suitable hydrolysing microorganism or nitrilase extract therefrom; and Rhodococcus Sp. NCIB 12218 or a mutant thereof, suitable for use in the process.

Description

Process for the preparation of difluorobenzamide

The present invention relates to a kind of 2, the preparation method of 6-difluorobenzamide.

EP-A-133 927(Nitto) disclosed that a kind of nitrile compound is converted into corresponding amide under certain suitable microbial process.These microorganisms can be improved their activity under the irradiation of light.The microorganism of the suitable specific type that is disclosed is a gram positive bacterium:

(a) Corynebacterium;

(b) Nocardia;

(c) bacillus;

(d) the motionless Pseudomonas of gemma;

(e) micrococcus sp; And

(f) brevibacterium sp.

The main application that is disclosed is to produce acrylamide and produce nicotinic acid from cyanopyridine from vinyl cyanide.Especially disclose the other acetonitrile that is converted into and be converted into ethanamide, methacrylonitrile is converted into Methacrylamide, valeronitrile is converted into valeramide, benzonitrile is converted into benzamide, and propionitrile is converted into propionic acid amide, and n-Butyronitrile is converted into positive butyramide, propane dinitrile is converted into Malonamide, sym-dicyanoethane is converted into succinic diamide, and flumaronitrile is converted into fumaramide, and chloromethyl cyanide is converted into chlor(o)acetamide and β-hydroxypropyl nitrile is converted into β-hydroxypropyl acid amides.

D.B.Harper is (" Microbial Metabolism of Aromatic Nitriles " in his " microbial metabolism of fragrant nitrile compound " literary composition, Biochem.J.(1977) 165,309-319) metabolism that utilizes Nocardia bacteria (rhodochrous group) NC IB11216 has been described, make benzonitrile generate phenylformic acid, and described the separation and the character of nitrilase.317 page tables 4 have disclosed the relative hydrolysis rate that utilizes various replacement benzonitrile enzymes to be hydrolyzed.It has illustrated that the steric hindrance of 2 bit substituents has very big influence to percent hydrolysis.Therefore 2-fluorine benzonitrile percent hydrolysis is lower than 30% of nitrile percent hydrolysis, and the percent hydrolysis of 2-benzyl chloride nitrile and 2-methyl benzonitrile is actually 0, while 4-fluorine benzonitrile, and the percent hydrolysis of 4-benzyl chloride nitrile and 4-methyl benzonitrile is obviously more much bigger than benzonitrile percent hydrolysis.Therefore can predict in the nature of things, have bigger sterically hindered 2,6-two replaces benzonitrile may be fully by enzymic hydrolysis.Harper finds 2 really, and 6-dichloro-benzonitrile (weedkiller Niagara 5006) is not even be hydrolyzed under high density yet.Even 3,5-dibromo benzonitrile (weedkiller bromoxynil) is not hydrolyzed in the high density enzyme yet, and is high more than 70% although the percent hydrolysis of 3-bromobenzyl nitrile is wanted.Harper has also put down in writing Verloop(Residue Rev43(1972) 55-103) find that single ortho position replaces the alkaline hydrolysis rate that reduces aromatic nitrile two ortho positions replacement and then suppresses this process fully.

Surprisingly find 2 now, 6-difluoro benzonitrile can be by microbial hydrolytic.Thereby, found unexpectedly that a kind of new microorganism can be with than the faster speed hydrolysis 2 of benzonitrile own, 6-difluoro benzonitrile.

So, can provide a kind of 2 according to the present invention, the preparation method of 6-difluorobenzamide, this method comprises makes 2, and 6-difluoro benzonitrile is subjected to a kind of suitable hydrolysising microorganism or the effect of its nitrilase extract.

Suitable hydrolysising microorganism can be the gram positive bacterium with nitrilase activity: Corynebacterium, Nocardia, bacillus, gemma motionless Pseudomonas, micrococcus sp and brevibacterium sp.But best microorganism is a kind of bacterium of Rhod.Microorganism itself just is applicable to preparation, but if necessary, the nitrilase extract that obtains from microorganism with currently known methods also can substitute.

The preferred sample of a kind of Rhod (Rhodococcos) bacterium is from Shell Haven Refinery, Stanford-le-Hope, Essex, a kind of soil isolate that the sludge treatment factory of England obtains, and the regulation of the internationally recognized budapest treaty of the patented procedure of storing according to related microorganism was stored in industrial microorganism country preservation center (NCIB), registration NCIB12218 on March 13rd, 1986.Here said microorganism is exactly " rhodococcus NCIB12218 ".It is CCTCC № M87060 that this bacterial strain is stored in Chinese typical culture collection center (CCTCC) preserving number on July 1st, 1987.

This new microorganism, rhodococcus NCIB12218, as after this described in detail, can be with than the faster rate hydrolysis 2 of its hydrolysis benzonitrile own, 6-difluoro benzonitrile.

The method according to this invention, microorganism be rhodococcus NC IB12218 or its mutant preferably, and rhodococcus NCIB12218 is easy to use.

The present invention also comprises rhodococcus NCIB12218 and mutant thereof.

Rhodococcus NCIB12218 mutant can separate and screening with the currently known methods breeding.Therefore sudden change can be to use chemical process, for example, causes with N-methyl-N '-nitro-N-nitrosoguanidine, also can be the physical method generation with ultraviolet radiation.

The present invention also comprises with 2 of the inventive method preparation, 2 of 6-difluorobenzamide and the such preparation of utilization, and the 6-difluorobenzamide removes to prepare Pesticidal compound again.

2, the 6-difluorobenzamide is known to be the intermediate of the known Pesticidal compound of preparation, the young urea (diflubenzuzon) that for example goes out (seeing US Patent specification the 1st, 324, No. 293).Utilize 2, the 6-difluorobenzamide comprises british patent specification the 1st, 460 as other method of insecticidal active compound intermediate, the method described in No. 419 and the EP-A-161019.

Being used for microorganism of the present invention can grow on a suitable known growth medium, and this substratum contains assimilable carbon source (for example glucose, lactose or sucrose), assimilable nitrogenous source (ammonium sulfate for example, ammonium nitrate or ammonium chloride), organic micro-nutrients source (yeast extract paste for example, malt extract, peptone or meat extract) and inorganic micro-nutrients (phosphoric acid salt for example, magnesium, potassium, calcium, manganese, zinc and/or molysite).

Bacterial growth in the presence of aerobic or air, stirs (for example vibration or stirring) usually, and temperature is 20-37 ℃ of scope, and pH carries out in the 5-9 scope.Available currently known methods is collected cultured cells, and according to the inventive method before using, if necessary, can be at agar slant freezing or freeze-drying preserve bacterial classification.

Realize that method of the present invention is very convenient, 0-37 ℃ of its temperature range, preferably under 20-30 ℃, pH scope 6-9, best 7-8, and illumination is preferably arranged.

Rhodococcus NCIB12218 has following characteristics and identifies through NCIB:

Test is carried out under 30 ℃, removes and indicates outgrowth at Oxoid CM ₃On the nutrient substance nutrient agar.

Cellular form

Under 30 ℃ at Oxoid CM ₁Nutrient broth+0.75%(weight) cultivate after 5 hours in the agar, cell is small-sized, parallel sides under 630 times of phase microscopes, slight curvature, or be curved bar-shaped.Some cells are agglomerate.

Gram-positive

Gemma-

Motility-

Colonial morphology

Cultivate after 3 days, bacterium colony is rounded, rule, and the edge is smooth, and surface smoothing is opaque, and low projection is rose pink, the about 1mm of diameter.

At glucose, peptone, water is cultivated on the sucrose medium

37 ℃ ± trace

45℃-

Catalase+

Oxydase, Kovacs-

The O-F glucose oxidase

" O-F glucose " promptly uses (J.Gen.Microbiol.26(1961) 133-140 of Hayward and Hodgkiss) oxidation-fermention medium production, and be supplemented with 1%(weight) the D-glucose of filtration sterilization, need cultivate 14 days with the sample of rhodococcus NCIB12218 inoculation.

Rhodococcus NCIB12218 can be stored on 4 ℃ of nutrient agar medium inclined-planes easily, or isolated cells is stored under-15 ℃ of low temperature in buffer culture medium.Have been found that cell can store one month down and loss of activity not at-15 ℃.

From following embodiment, can further understand the present invention.

Embodiment 1

Growth medium is pressed following set of dispense system:

0.2g K ₂HPO ₄

0.2g MgSO ₄.7H ₂O

2.5mg FeSO ₄.7H ₂O

12.5mg CaCl ₂.2H ₂O

2.5mg MnSO ₄.3H ₂O

1.0g （NH ₄） ₂SO ₄

10g glucose

The 5g peptone

The 3g yeast extract paste

The 3g malt extract

Above-mentioned component is dissolved in the 900ml water, transfers pH to 7.2 with hydrochloric acid, and adding water again, to make solution be 1 liter.

The above-mentioned growth medium of 50ml is packed in the 250ml Erlenmeyer flask, also cultivates 48 hours on shaking table under 30 ℃ with rhodococcus NCIB12218 inoculation.

Centrifugal collecting cell (on " Sorvall " (registered trademark) whizzer, 20,000rpm, 15 minutes), with the washing of 50mMpH8 phosphate buffered saline buffer, centrifugal again and resuspending is in the 2.5ml damping fluid.Take out the sub-fraction sample of suspension, be used to detect its dry cell weight.

A certain amount of suspension contains 0.5mg dry weight rhodococcus NCIB12218 as calculated, is diluted to 1ml with above-mentioned damping fluid.Suspension remains on 25 ℃ and also shone 5 minutes at the 25cm place with a 60W tungsten lamp, adds 1mg2 then, 6-difluorobenzyl nitrile (DFBN).Add Continuous irradiation after the DFBN, make mixed solution remain on 25 ℃ 15 minutes.Take out sample subsequently and analyze DFBN and 2 with gas-chromatography (gc), 6-difluorobenzamide (DFBAM) is with the detection reaction degree.

With benzonitrile and 2, the 6-dichloro-benzonitrile replaces DFBN to repeat said process as a comparison.The result lists table 1 in:

Table 1

Substrate product productive rate

2,6-difluoro benzonitrile 2., 6-difluorobenzamide 25.5g/g cell/hour

(the 0.178mol/g cell/hour)

Benzonitrile benzamide 15.6g/g cell/hour

(the 0.146mol/g cell/hour)

2,6-dichloro-benzonitrile 2,6-dichloro-benzamide 0.053g/g cell/hour

(3 * 10 ^-4The mol/g cell/hour)

Embodiment 2

In the growth medium of 400ml embodiment 1, inoculate rhodococcus NCIB12218 and descend cultivation 48 hours at 30 ℃.

Collect and cultivate gained cell and washing (method is with embodiment 1), with the cell suspension (with embodiment 1) in 2 liters of phosphate buffered saline buffers of 440mg dry weight.

Cell suspending liquid shone 5 minutes apart from the 25cm place in 25 ℃ of stirrings (magnetic agitation) and with three 60W tungsten lamps in a glass beaker.Add 75g DFBN, mixed solution has under the illumination condition to keep 16 hours at 25 ℃.Gc analysis this moment (gc) shows that 98.9% DFBN is converted into DFBAM.

DFBAM-forms and just crystallizes out from solution.Can directly reclaim this crystal settling.If recrystallization can get 50.3g DFBAM crystal from ethyl acetate.After reaction mixture cooling and the evaporation, also separable 16g DFBAM.

Embodiment 3

To join in the 1ml n-heptane solution that contains 5 μ lDFBN by 50 μ l rhodococcus NCIB12218 phosphate buffered liquid suspensions of preparation of embodiment 2 methods and irradiation.Continue irradiation and stirring under the room temperature.Crystalline deposit.Add 10 μ lDFBN after one and a half hours again.After-filtration went out crystal in 18 hours.Analysis revealed DFBN virtually completely is converted into DFBAM.

Embodiment 4

Prepare a rhodococcus NCIB12218 cell suspending liquid by embodiment 1 and 2 usefulness phosphate buffered saline buffers.3.2ml this suspension is also pressed embodiment 2 described irradiations 5 minutes in 25 ℃ of stirrings (magnetic agitation) in a glass beaker.Adding normal heptane to volume is 50ml.Under 28 ℃ of temperature, continue irradiation and stirring, and add 3.24g DFBN.The gas liquid chromatography analysis revealed, 92%DFBN is converted into DFBAM after 5 hours.

Claims (1)

1, preparation 2, the method for 6-difluorobenzamide, this method comprises makes 2, and 6-difluoro benzonitrile is subjected to the effect of rhodococcus CCTCCNoM87060, separates 2 subsequently, the 6-difluorobenzamide.